Updated:  Greater Brisbane aged care homes, hospitals and disability services remain closed to visitors for another 72 hours as authorities remain on-edge over a potential COVID-19 outbreak.

Queensland has recorded two cases of COVID-19, both in hotel quarantine.

The extension comes amid fears people released from quarantine at the Hotel Grand Chancellor could have been exposed to COVID-19.

Hospitals and aged care and disability services in Greater Brisbane will be locked down for at least 72 hours after the discovery of the first locally transmitted coronavirus case in Queensland in 59 days.

Premier Annastacia Palaszczuk made the announcement on Saturday morning after a female doctor at the Princess Alexandra Hospital returned a positive test.

The doctor worked with two COVID-19-positive patients on Wednesday, and was in the community on Thursday while possibly infectious.

The two patients, who had been in hotel quarantine, tested positive to the UK variant of COVID-19 and it was expected that the doctor would, too, Ms Palaszczuk said.

Health authorities released a list of potential exposure sites the doctor visited on Wednesday.

They include three “high-risk sites” in the Morning After cafe at West End, Corporate Box gym at Greenslopes and the Stones Corner Hotel.

McDonalds at Coorparoo has been identified as a low-risk site.

For the next three days, all essential visitors to hospital and other facilities for vulnerable people will be required to wear a mask, though there is no requirement for mask-wearing in the community, Ms Palaszczuk said.

Princess Alexandra Hospital was placed into lockdown on Friday night, as contact tracers searched for patients, staff and families who may have been exposed.

In a statement on Friday, the hospital said “tests indicate low levels of the virus, which means the staff member may have only been infectious in the community for around one day on the 11th”.

From Friday night, all non-essential visits to the hospital were banned, and any essential visitors and staff were required to wear a mask.

The Emergency Department is still open, but the people are urged to use other hospitals or a GP, if possible.

Non-urgent outpatient bookings and elective surgery have been postponed.